Models of Stroke

Our lab uses models of stroke. In cell culture models, we mimic the ischemia, or lack of blood supply, by depriving cells in culture of oxygen and glucose.

There are three principal cell types in the brain: Neurons, glia and vascular cells. The involvement and responses of each of these cell types can be distinguished in cell cultures containing one cell type, or combinations of any of the three types. The use of specific reagents such as antibodies specific to proteins in each cell, allow us to distinguish the cell types using fluorescent microscopy.

In the figure at right, the image shows cultures at high magnification (scale bar on right is equal to 20 micrometers). The neurons are stained red, astrocytes (a type of glia) are green and the nuclei of all the cells are stained blue.

When some of these cultures are exposed to oxygen and glucose deprivation (OGD) in the special chamber shown, the neurons die through a process called apotosis (white arrows in culture image on right).

The results of many experiments are shown in the bar graph below. The percentage of neurons which are apoptotic increases after 60 minutes of OGD. However, there is no apparent effect on the astrocytes. It is known that astrocytes are beneficial for neurons, and harnessing the protective pathways in these special cells may yield promising approaches to reduce injury following stroke.